Electromagnetic device



Nov. 17, 1925. r 1,562,200

, W. O. BECK ELECTROMAGNETIC DEVICE Filed Aug. 29. 1923 pawl for the stepping Patented Nov. 17, 1925.

UNITED STATES PATENT OFFICE.

WILLIAM O. BECK, 0F RIDGEFIELD, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTROMAGNETIC DEVICE.

Application filed August 29, 1923. Serial No. 659,881.

To all whom it may concern:

Be it known that I, WILLIAM O. BECK, a citizen of the United States of America, residing at Ridgefield, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Electromagnetic Devices, of which the following is a full, concise, clear, and exact description.

This invention relates to electromagnetic devices, and more particularly to electromagnetic relays of the type wherein the closure of an electrical circuit is delayed for a definite interval of time.

Among the objects of the invention is to provide an improved device of this character which will operate in an accurate and simple manner.

To attain the objects of the invention a pair of electromagnets are employed which jointly control a ratchet mechanism, which in turn controls a local circuit. More specifically, one electromagnet controls a stepping device and an interrupting circuit and the other electromagnet controls a retaining device. The core of one of the electromagnets is hollow. A shaft connected to the armature of the other electro-magnet extends through the hollow and controls the retaining pawl. A compact and unitary structure is thus provided.

Another feature is the provision of adjustable means for varying the actuation of the circuit closing device.

Other features of the invention will be apparent from the following description and appended claims, reference being had to the accompanying drawings wherein Fig. 1 is a bottom lan. partly in section,

Fig. 2 is a top plan f the relay.

Fig. 3 is an end elevation.

' Fig. 4 is a cross section taken on the line 4-4 of Fig. 1 looking in the direction of the small arrows.

Fig. 5 is a schematic nections of the relay.

Referring to the drawings, a U-shaped member 1 of magnetic material serves as a pole piece for magnet coils 2 and 3 mounted between parallel sides thereof. Coil 2 has a hollow core 4 which is joined to pole piece 1 by means of the screw 5. Lugs 6 formed inwardly from the sides of the U-shaped member 1 serve as a pole face for coil 2. Coil 3 is supported at one end by bracket 7, which is made of magnetic material and dia ram of the conis adjustablymounted a contact controlling member 13, preferably of insulating material. This member 13 is adapted to close contacts 14 of a circuit connected to the terminals 40 and to break contacts 15 of the relay energizing circuit connected to terminals 41, when the ratchet wheel 12 rotates the member 13 into engagement with the springs 16 and 17 respectively. Threaded on the other end of theshaft 10 is a shouldered adjusting collar 18. Within the core 9 andsurrounding the shaft 10 is a spring 22, one end of whlch is attached to the shaft and the other end to a collar 24 mounted in core 9 and having a flange adapted to be clamped to bracket 7 by means of screw 24 in various positions. To adjust the tension of spring 23 sufliciently to return the shaft and ratchet wheel to normal position, that is, so that a projection 25 on the ratchet wheel engages a stop 26 secured to member 1.

Extending into the hollow core 4 is a nonmagnetic plunger 19 seated on a coil spring 20 tending to force the plunger outward.

The other end of the plunger 19'is fastened to the center of a circular armature 11 which is in position to be attracted by pole faces 6 when coil 2 is energized. A bridge member 21 is rigidly mounted on armature 11, as shown in-Figs. 1 and .4, and serves as a coupling between the armature 11 and the shaft 10. The collar 18 on shaft 10 is fitted into a slot 22 on bridge member 21 so that i the shaft 10 and the ratchet wheel 12 will move longitudinally with armature 11. The collar 18 fits loosely in the slot 22 so that the shaft 10 is free to rotate and is adjustable on the shaft to regulate the air gaps between the armature 11 and pole pieces 6. Hinged at 27 to one side of member 1 is an armature 28 which causes a stepping pawl 29' attached thereto to engage the ratchet wheel 12 and rotate it one step when the armature 28 is attracted by core 9. Mounted on member 1 at one side of ratchet wheel 12 is a retaining pawl 30 therefor. This pawl is normally out of engagement with the ratchet wheel 12 but engages it when armature 11 is attracted and moves shaft and ratchet wheel 12 longitudinally.

The armature 28 controls the energizing circuit for coils 3 at contacts 31, which circuit is broken when the attracted armature reaches the end of its stroke by reason of the arm 32, carried by the armature, engaging the spring 33. The circuit closing member 13 is pivoted to the ratchet wheel 12 at 34 and is held in any desired position thereon by the set screw 35 which extends through the slot 36 in member 13.

The operation of the device is as follows;

Referring to Fig. 5, when current is connected to the main circuit 37 as for example by the closure of a switch 38, magnets 2 and 3 are energized in parallel over an obvious circuit. Magnet 2 attracts its armature 11 which, through the medium of the bridge 21 and the shaft 10 (Fig. 1) draws the ratchet wheel 12 into engagement with its retaining pawl 30. Magnet 3 alternately attracts and releases its armature 28 due to the fact that the energizing circuit for magnet 3 is completed through normal contacts' controlled by the armature and thus the ratchet wheel is stepped ahead against the tension of spring 23. lVhen the contact closing member 13 has been rotated into engagement with contact springs 16, the contacts 14 of the local circuit are closed. The continued rotation of member 13 causes it to engage contact springs 17 which opens the energizing circuit for magnet 3 at contacts thereby discontinuing the stepping operation.

Due to magnet 2 being in parallel with magnet 3 but not under control of the above mentioned contacts, it continues to hold its armature and, consequently, the ratchet wheel 12 is retained in engagement with its retaining pawl 30, thus preventing its return tonormal until the main circuit 37 is broken. lVhen the magnet 2,is 'deenergized by the opening of the main circuit the ratchet wheel 1.2 is moved out of engage ment with the retaining pawl by spring 20 and is rotated back to normal and intothrough a hollow core of one of said electroengagement with stop 26 under tension of spring 23.

It will readily be seen that a considerable interval of time elapses between the closure of the main circuit and the closure of'the local circuit due to the time consumed in stepping the ratchet wheel into proper position. It will be evident therefore that any desired delay, up to approximately thetime required to'step the ratchet wheel one complete revolution, can be secured by the proper positioning of the member 13 by means of .set screw 35, which can be removed and placed in other properly positi threaded openings, such as 39, in the ratchet wheel.

lVhat is claimed 1s:

1. In a slow acting relay, an electromag net, an armature and an energizing circuit therefor, a ratchet wheel moved thereby, retaining means for said ratchet wheel, a switchv controlled by said ratchet wheel, a second electromagnet connected across said energizing circuit and an armature therefor, said armature being in a plane parallel to that of the ratchet wheel and adapted to move said ratchet wheel into engagement with. saidv retaining means.

2. In combination, a hollow coredv electromagnet having a stepping armature, a shaft extending through said hollow core, a ratchet wheel fixed at one end of said shaft and adapted to be rotated by said armature, a retaining pawl for said ratchet wheel normally out of engagement therewith, a second electromagnet, an armature therefor mounted at the other end of said shaft and adapted when said second electromagnet is energized to move said ratchet wheel into engagement with its retaining pawl, and electrical contacts adapted to be controlled when said ratchet wheel is rotated to a predetermined position.

3. Ina time relay, an energizing circuit, a source of current therefor, a circuit to be controlled, an electromagnet in said energizing circuit, a ratchet wheel, means associated therewith for opening the last men tioned circuit when said ratchet wheel is rotated into a predetermined position. means including an armature associated with said electromagnet adapted to step said ratchet wheel. when said electromagnet is energized, a retaining pawl for the ratchet wheel normally out of engagement therewith, a second electromagnet in parallel to said first electromagnet across said energizing circuit, and an armature therefor adapted to move said ratchet wheel into engagement with said'retaining pawl and to maintain said ratchet wheel in its operated position after the energizing circuit of said first magnet is opened.

4. In a time relay, electromagnetsa 'a ratchet wheel, mounted on a shaft extending magnets, a retaining pawl for said ratchet wheel normally out of engagement therewith, a switch controlled by said ratchet wheel, an armature controlled by said electromagnet and adapted to advance said ratchet wheel, and a second armature mounted on said shaft and controlled by another of said electromagnets for moving said ratchet wheelinto engagement with its retaining pawl.

5. In a time relay, an electromagnet, an armature controlled thereby, a ratchet wheel adapted to e rotated bv said stepping armature, adjustable circuit closing means carried by said ratchet wheel, contacts controlled by said means, a retaining pawl normally out of engagement with said ratchet wheel, and a second armature adapted to move said ratchet wheel into engagement with said retaining pawl.

6. In combination, a switch, and means for actuating the same comprising a pawl and ratchet mechanism, and electromagnetic means for operating said mechanism, another electromagnetic means for placing said mechanism under the control of said first mentioned electromagnetic means, adjustable circuit closing means associated with and mounted on said mechanism to actuate the switch a predetermined time after the operation of said mechanism, and a U-shaped member enclosing said first and second named electromagnetic means for providing a common magnetic Path therefor.

7. In combination, a switch, and means for controlling the operation thereof comprising an electromagnet, an armature and stepping pawl actuated thereby, a ratchet wheel adapted to be operated by said pawl, a retaining pawl normally out of engagement with said wheel, another electromagnet for placing said wheel under control of said retaining pawl, and an arm adjustably mounted on said wheel to make contact with a portion of said switch to cause the operation thereof after the wheel has advanced a predetermined number of steps corresponding to a particular adjustment.

8. In combination, a switch, and means for operating the same comprising electromagnets, energizing circuits therefor, means controlled by said magnets to operate the switch a predetermined time interval after the energization of said magnets, and another switch operating approximately at the same time as the first mentioned switch to break the energizing circuit for one of said n'iagnets to maintain said first mentioned switch in operated position.

5). In combination, a switch and means for operating the same comprising an electromagnet, an energizing circuit therefor, another electromagnet provided with interrupting contacts, an energizing circuit for said second magnet including said interrupting contacts, mechanism under joint control of said magnets to operate said switch a predetermined time interval after the en ergization of said magnets, and means controlled by said mechanism for breaking said interrupting circuit to maintain said switch in operated position under control of said first mentioned circuit.

10. In an electromagnetic device, a ratchet wheel, a retaining pawl therefor normally out of engagement therewith, a switch controlled by said ratchet wheel, an electromagnet, an armature controlled thereby adapted to advance said ratchet wheel to operate said switch, a hollow magnetic core for said electromagnet, a second electromagnet, an armature controlled thereby, a shaft connecting said ratchet wheel and said second armature and extending through the hollow core of said first electromagnet to move said ratchet wheel into engagement with its retaining pawl when said second electromagnet is energized, and a common U-shaped magnetic structure for said electromagnets.

11. In combination, a U-shaped magnetic structure enclosing an electromagnet, a shaft movable within the core of said electromagnet, a ratchet mechanism actuated by said electron'iagnet for controlling a switch comprising a ratchet wheel mounted on said shaft and a retaining pawl for said ratchet wheel normally out of engagement therewith, and a second electromagnet also enclosed by said U-shaped structure having an armature mounted on said shaft to move said ratchet wheel into engagement with said retaining pawl when said second electromagnet is energized.

12. In combination, a U-shaped magnetic structure, electromagnets enclosed therein, a shaft movable within the core of one of said electromagnets and attached to the armature of another of said electromagnets, and a ratchet mechanism jointly controlled by bot-h of said electromagnets for operating a switch.

In witness whereof, I hereunto subscribe my name this 24 day of August A. D, 1923.

IVILLIAM O. BECK. 

